|
Originally published In Press as doi:10.1074/jbc.M505636200 on July 8, 2005
J. Biol. Chem., Vol. 280, Issue 37, 32141-32147, September 16, 2005
DNA-induced Secondary Structure of the Carboxyl-terminal Domain of Histone H1*
Alicia Roque ,
Ibon Iloro ,
Imma Ponte ,
José Luis R. Arrondo , and
Pedro Suau 1
From the
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad Autónoma de Barcelona, 08193 Bellaterra, Barcelona, Spain and the Departamento de Bioquímica, Universidad del País Vasco, Apartado. 644, E-48080, Bilbao, Spain
We have studied the secondary structure of the carboxyl-terminal domains of linker histone H1 subtypes H10 (C-H10) and H1t (C-H1t), free in solution and bound to DNA, by IR spectroscopy. The carboxyl-terminal domain has little structure in aqueous solution but becomes extensively folded upon interaction with DNA. The secondary structure elements present in the bound carboxyl-terminal domain include the -helix, -structure, turns, and open loops. The structure of the bound domain shows a significant dependence on salt concentration. In low salt (10 mM NaCl), there is a residual amount of random coil, 7% in C-H10 and 12% in C-H1t. In physiological salt concentrations (140 mM NaCl), the carboxyl termini become fully structured. Under these conditions, C-H10 contained 24% -helix, 25% -structure, 17% open loops, and 33% turns. The latter component could include a substantial proportion of the 310 helix. Despite their low sequence identity ( 30%), the representation of the different structural motifs in C-H1t was similar to that in C-H10. Examination of the changes in the amide I components in the 2080 °C temperature interval showed that the secondary structure of the DNA-bound C-H1t is for the most part extremely stable. The H1 carboxyl-terminal domain appears to belong to the so-called disordered proteins, undergoing coupled binding and folding.
Received for publication, May 23, 2005
, and in revised form, June 27, 2005.
* This work was supported by Ministerio de Educación y Ciencia Grants BMC2002-00087 and BMC2002-01438, Generalitat de Catalunya Grant 2001SGR 00199, and University of the Basque Country Grant 00042.310-13552/2001. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 To whom correspondence should be addressed. Tel.: 34-93-5811391; Fax: 34-93-5811264; E-mail: pere.suau{at}uab.es.

CiteULike Complore Connotea Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
A. Roque, I. Ponte, J. L. R. Arrondo, and P. Suau
Phosphorylation of the carboxy-terminal domain of histone H1: effects on secondary structure and DNA condensation
Nucleic Acids Res.,
August 1, 2008;
36(14):
4719 - 4726.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. M. Eirin-Lopez, J. D. Lewis, L. A. Howe, and J. Ausio
Common Phylogenetic Origin of Protamine-like (PL) Proteins and Histone H1: Evidence from Bivalve PL Genes
Mol. Biol. Evol.,
June 1, 2006;
23(6):
1304 - 1317.
[Abstract]
[Full Text]
[PDF]
|
 |
|
Copyright © 2005 by the American Society for Biochemistry and Molecular Biology.
|
Advertisement
Advertisement
|